Substrate processing method and substrate processing apparatus

1 . A substrate processing method, comprising:

placing a substrate with a dielectric film on a substrate support in a chamber; and

etching the dielectric film with plasma generated from a reaction gas containing an HF gas and at least one C x H y F z gas selected from the group consisting of a C 4 H 2 F 6 gas, a C 4 H 2 F 8 gas, a C 3 H 2 F 4 gas, and a C 3 H 2 F 6 gas,

wherein the etching includes setting a temperature of the substrate support to be 0° C. or lower and setting a flow rate of the HF gas to be greater than a flow rate of the C x H y F z gas, and

the reaction gas further contains a phosphorus halide-containing gas containing both phosphorus and at least one of Cl, Br, or I.

2 . The substrate processing method according to claim 1 , wherein

the flow rate of the C x H y F z gas is less than or equal to 20% by volume of a total flow rate of the reaction gas.

3 . The substrate processing method according to claim 1 , wherein

the flow rate of the HF gas is greater than or equal to 70% by volume of a total flow rate of the reaction gas.

4 . The substrate processing method according to claim 1 , wherein

the reaction gas further contains an oxygen-containing gas.

5 . The substrate processing method according to claim 1 , wherein

the reaction gas further contains at least one gas selected from the group consisting of a boron-containing gas and a sulfur-containing gas.

6 . The substrate processing method according to claim 1 , wherein

the plasma is generated from a process gas containing the reaction gas and an inert gas.

7 . The substrate processing method according to claim 1 , wherein

the substrate includes a mask including an organic film defining at least one opening on the dielectric film or a metal-containing film defining at least one opening on the dielectric film.

8 . The substrate processing method according to claim 1 , wherein

the etching includes providing a direct-current voltage or low-frequency power to an upper electrode facing the substrate support.

9 . The substrate processing method according to claim 1 , wherein

the reaction gas further contains a halogen-containing gas.

10 . The substrate processing method according to claim 9 , wherein

the halogen-containing gas is at least one gas selected from the group consisting of a chlorine-containing gas, a bromine-containing gas, and an iodine-containing gas.

11 . The substrate processing method according to claim 9 , wherein

the halogen-containing gas is at least one gas selected from the group consisting of Cl 2 , SiCl 2 , SiCl 4 , CCl 4 , SiH 2 Cl 2 , Si 2 Cl 6 , CHCl 3 , SO 2 Cl 2 , BCl 3 , PCl 3 , PCl 5 , POCl 3 , Br 2 , HBr, CBr 2 F 2 , C 2 F 5 Br, PBr 3 , PBr 5 , POBr 3 , BBr 3 , HI, CF 3 I, C 2 F 5 I, C 3 F 7 I, IF 5 , IF 7 , I 2 , and PI 3 .

12 . The substrate processing method according to claim 1 , wherein

the dielectric film is a silicon-containing film.

13 . The substrate processing method according to claim 12 , wherein

the silicon-containing film includes at least one film selected from the group consisting of a silicon oxide film, a silicon nitride film, and a polysilicon film.

14 . The substrate processing method according to claim 1 , wherein

the etching includes applying an electrical bias to the substrate support,

a period during which the electrical bias is applied to the substrate support includes a first period and a second period that alternates with the first period, and

a level of the electrical bias in the first period is zero or at a first level, and a level of the electrical bias in the second period is at a second level higher than the first level.

15 . The substrate processing method according to claim 14 , wherein

the etching includes providing radio-frequency power for generating the plasma to the substrate support or to an upper electrode facing the substrate support,

a period during which the radio-frequency power is provided includes a third period and a fourth period that alternates with the third period,

a level of the radio-frequency power in the third period is zero or at a third level, and a level of the radio-frequency power in the fourth period is at a fourth level higher than the third level, and

the second period and the fourth period at least partially overlap.

16 . The substrate processing method according to claim 14 , wherein

the electrical bias is a pulsed voltage.

17 . The substrate processing method according to claim 1 , wherein

the etching includes

a first process of setting a pressure inside the chamber to a first pressure, applying a first electrical bias to the substrate support, and etching the dielectric film, and

a second process of setting the pressure inside the chamber to a second pressure, applying a second electrical bias to the substrate support, and etching the dielectric film, and

the first pressure differs from the second pressure or the first electrical bias differs from the second electrical bias, or the first pressure differs from the second pressure and the first electrical bias differs from the second electrical bias.

18 . The substrate processing method according to claim 17 , wherein

the first pressure is higher than the second pressure.

19 . The substrate processing method according to claim 17 , wherein

an absolute value of the first electrical bias is greater than an absolute value of the second electrical bias.

20 . The substrate processing method according to claim 17 , wherein

the first process and the second process are repeated alternately.

21 . A substrate processing method, comprising:

placing a substrate with a silicon-containing film including a silicon oxide film on a substrate support in a chamber; and

etching the silicon-containing film with plasma generated from a reaction gas containing a fluorine-containing gas and a C x H y F z gas being a gas different from the fluorine-containing gas, where x is an integer greater than or equal to 2, and y and z are integers greater than or equal to 1,

wherein the etching includes setting a temperature of the substrate support to be 0° C. or lower and setting a flow rate of the C x H y F z gas to be less than or equal to 20% by volume of a total flow rate of the reaction gas, and

the reaction gas further contains a phosphorus halide-containing gas containing both phosphorus and at least one of Cl, Br, or I.

22 . The substrate processing method according to claim 21 , wherein

the fluorine-containing gas is a gas to produce an HF species in the chamber.

23 . The substrate processing method according to claim 21 , wherein

a flow rate of the fluorine-containing gas is highest among flow rates of all gases in the reaction gas.

24 . The substrate processing method according to claim 21 , wherein

the C x H y F z gas includes one or more CF 3 groups.

25 . The substrate processing method according to claim 24 , wherein

the C x H y F z gas contains at least one gas selected from the group consisting of a C 3 H 2 F 4 gas, a C 3 H 2 F 6 gas, a C 4 H 2 F 6 gas, a C 4 H 2 F 8 gas, and a C 5 H 2 F 6 gas.

26 . A substrate processing method, comprising:

placing a substrate with a silicon-containing film including a silicon oxide film on a substrate support in a chamber;

generating plasma in the chamber; and

etching the silicon-containing film using an HF species and a C x H y F z species in the plasma, where x is an integer greater than or equal to 2, and y and z are integers greater than or equal to 1,

wherein the plasma includes a greatest amount of the HF species among all species in the plasma, and

the plasma further contains a phosphorus halide-containing species containing both phosphorus and at least one of Cl, Br, or I.